JPH0484961A - Heat generating method of body warmer formed by using hydrogen occluding alloy and body warmer - Google Patents

Abstract

PURPOSE:To obtain the heating method for the body warmer which does not require a heat source for heat generation or a special firing device and has a large calorific value and the body warmer by gradually releasing hydrogen from a container in which a hydrogen occluding alloy is hermetically sealed and bringing the released hydrogen into contact with a catalyst, thereby executing the combustion. CONSTITUTION:This body warmer is constituted of the container 3 in which the hydrogen occluding alloy 2 occluded with hydrogen is hermetically sealed and a catalyst holding part 5 which is held internally with the catalyst 4. The container 3 and the catalyst holding part 5 are constituted as separate bodies. The container is replaced next time with a fresh container 3 after the release of the hydrogen from the hydrogen occluding alloy 2 hermetically closed in the container 3 ends and the combustion of the body warmer 1 is completed so that the combination use with the previously used catalyst holding part 5 is executed. For example, a rare earth system (LaNi5, etc.), Ti system (T1.2Mn1.8, TiMn1.5, TiFe, etc., Mg system (Mg2Ni, etc.), Zr system (ZrMn2, etc.), MmNiCo, etc., are usable as the hydrogen occluding alloy 2. The body warmer generates heat by natural ignition in this way and generates the heat quantity of about 3 times the heat quantity of benzene, etc., per unit weight.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of generating heat from a hand warmer and a hand warmer using a metal hydride that stores inexhaustible, odorless and clean hydrogen as a fuel. .

[Conventional technology]

Hand warmers have traditionally been widely used as heating devices, and there are some that use benzine as fuel, and some that are disposable that use iron powder to oxidize and generate heat.

The catalytic combustion hand warmer, which uses benzine as fuel, generates an extremely high amount of combustion heat per unit weight, about seven times the amount of heat produced by oxidation of iron powder, and is inexpensive and highly economical.

However, when igniting, a heat source or some kind of ignition device is required to start the catalytic combustion of benzine. Another drawback was the characteristic odor of benzine during combustion. Furthermore, although it generates a much higher amount of heat than the oxidation heat of iron powder, there is a limit to the amount of heat generated per unit weight.

[Problem to be solved by the invention]

Therefore, the present invention aims to provide a method of generating heat for a hand warmer and a hand warmer that does not require a heat source or special ignition device, is odorless, and generates a large amount of heat per unit weight.

Means for Solving Problem C] In order to achieve the above object, the present invention takes the following technical means.

In the invention of a heating method for a pocket warmer using a hydrogen storage alloy, a hydrogen storage alloy (2) that stores hydrogen is sealed in a container (3).
Hydrogen was gradually released from the catalyst, and the released hydrogen was brought into contact with the catalyst (4) and combusted.

Further, hydrogen is gradually released by unsealing the container (3) in which the hydrogen storage alloy (2) which has stored hydrogen is sealed, and the released hydrogen is brought into contact with the catalyst (4) and combusted. After that, hydrogen in the hydrogen storage alloy (2) may be gradually released by receiving the heat of the combustion, and the released hydrogen may be brought into contact with the catalyst (4) and combusted.

Another catalyst (7) whose surface is resistant to oxidation and has high low-temperature activity may be mixed into the catalyst (4).

The invention of a pocket warmer using a hydrogen storage alloy includes a container (3) in which a hydrogen storage alloy (2) that stores hydrogen is sealed, a means for opening the container (3), and a means for opening the container (3). A catalyst (
4).

Another catalyst (7) whose surface is resistant to oxidation and has high low-temperature activity may be mixed into the catalyst (4).

[Effect]

As a result of the above configuration, the hydrogen gradually released from the hydrogen storage alloy (2) that has stored hydrogen in the container (3) comes into contact with the catalyst (4) and spontaneously ignites and generates heat. , generates about three times the amount of heat per unit weight of benzine, etc.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of generating heat for a hand warmer and a hand warmer using a hydrogen storage alloy according to the invention of this application will be explained with reference to the drawings shown as examples.

In the figure, (1) is a pocket warmer according to the present invention, and a container (3) in which a hydrogen storage alloy (2) that stores hydrogen is sealed.
and a catalyst holding part (5) holding the catalyst (4) therein.
It consists of.

The container (3) and the catalyst holding part (5) are configured as separate bodies, and the release of hydrogen from the hydrogen storage alloy (2) sealed in the container (3) has been completed, and the combustion of the hand warmer (1) has been completed. Next time, it can be replaced with a new container (3) so that it can be used in combination with the catalyst holding part (5) used last time.

As the hydrogen storage alloy (2), for example, rare earth-based (La
Ni, etc.), Ti-based (T i r, t M n 1.
a, TiMn, s, TiFe, etc.), Mg-based (Mg
zNi, etc.), Zr-based (ZrMnz, etc.), MmNiC.

etc. can be used.

This hydrogen storage alloy (2) is made to store hydrogen by a known method to obtain a metal hydride.

However, the metal hydride is not limited to these, and any metal hydride having a hydrogen dissociation equilibrium pressure of 1 atm or more and less than 10 atm at room temperature can be used as appropriate.

However, if the hydrogen dissociation equilibrium pressure is 9 atm or more, the dissociation equilibrium pressure will be 10 atm or more at a temperature of 30°C or more in summer, so it is necessary to make the container (3) a pressure-resistant structure or install a safety valve. However, it is large and heavy, which is inappropriate from a safety standpoint. Therefore, it is desirable to use a pressure of 1 atm or more and less than 9 atm.

In order to use hydrogen as fuel without using a hydrogen storage alloy, it is necessary to have a built-in fuel tank that stores hydrogen in the body of the hand warmer, but conventional liquefied hydrogen or compressed hydrogen cannot explode. The possibility of this being extremely high made it completely impossible to put it into practical use.

The hand warmer of the present invention makes it possible to release hydrogen extremely safely by housing a hydrogen storage alloy in which hydrogen is stored in the container.

The container (3) has a cylindrical shape made of metal with a bottom and consists of two layers: an inner cylinder (31) and an outer cylinder (32), and the inner cylinder (31) is made of a hydrogen storage alloy (2) that stores hydrogen. is sealed, and an air layer (33) is interposed between the inner cylinder (31) and the outer cylinder (32).

The reason for the two-layer structure is that in the unlikely event that the hand warmer (1) according to the present invention is exposed to high temperatures, hydrogen will be absorbed and hydrogen will be released from the metal hydride hydrogen storage alloy (2). This is because the internal pressure of the container (3) may become high.

A thin metal film sealing plug (35) is provided at the tip of the reduced diameter part (34) provided above the container (3), and the outer periphery of the reduced diameter part (34) is equipped with a catalyst retainer, which will be described later. The threaded groove is formed so as to be screwed into the open enlarged diameter part (51) provided in the part (5).

An O-ring (36) is inserted into the reduced diameter portion (34) to ensure an airtight state when the reduced diameter portion (34) is screwed and connected to the open enlarged diameter portion (51).

The catalyst holding part (5) has a casing (
52) and the following provided inside the casing (52).

A combustion chamber (53) is located above the inside of the casing (52).
However, there is a trumpet-shaped part (54) below the combustion chamber (53).
A connecting portion (55) for connecting to the container (3) is located below the cup-like portion (54).

In the combustion chamber (53), the catalyst (4) is fixed on the holding frame (56), and the outer wall of the combustion chamber (53) has air introduction holes (57) for supplying air for combustion. ) are drilled in multiple locations.

As the catalyst (4), platinum catalysts using glass fibers, ceramics, alumina, porous metals such as aluminum, etc. as carriers can be used, but in this example, glass fibers are formed into a mat shape. A platinum catalyst that was made breathable was used.

In this catalyst (4), it is preferable to embed at least one other catalyst (7) whose surface is less likely to be oxidized and has high low-temperature activity, that is, the catalyst is likely to be activated at low temperatures. For example, a palladium catalyst or an alloy catalyst can be used.

This is because once combustion occurs on the catalyst (4), an oxide film is formed, making it difficult to start the reaction a second time.

Conventionally, this oxide film was removed by igniting it using an ignition device and applying heat, but other catalysts (7) that are resistant to oxidation and have high low-temperature activity as described above are mixed in at least one location. With this in mind, we made it easier to start the reaction from the second time onward.

The oxidation reaction starts from this highly active catalyst (7) at low temperature,
This heat is conducted to the surroundings and the entire catalyst (4) is ignited.

Therefore, when the container (3) in which the hydrogen storage alloy (2) is sealed is replaced, the catalyst holding part (5) can be used repeatedly without the need for ignition.

The lower trumpet-shaped part (54) of the combustion chamber (53) is for uniformly guiding the hydrogen released from the lower container (3) to the catalyst (4); A connecting portion (55) having a threaded groove is formed.

The connecting portion (55) includes an open enlarged diameter portion (51) whose diameter is enlarged below the trumpet-shaped portion (54), and an open enlarged diameter portion (51) that faces from near the center of the trumpet-shaped portion (54). , container (3)
and a communicating thin tube (58) as a means for opening the seal.

The communicating narrow tube (58) is connected to the thin film-like sealing stopper (3) of the container (3).
5) to guide the hydrogen in the container (3) to the combustion chamber (53) through the inside of this narrow communication tube (58).

The hydrogen released in the container (3) is transferred from the communicating tube (58) that pierced through the sealing plug (35) to the container (3) and the catalyst holding part (5).
), the combustion chamber (
53).

Next, the usage condition of this pocket warmer (1) will be explained.

The reduced diameter part (34) of the container (3) and the open enlarged diameter part (51) of the catalyst holding part (5) are screwed together and tightened to form a communicating narrow tube (58).
) to break through the sealing stopper (35) to unseal the container (3) containing the hydrogen storage alloy (2) that has stored hydrogen.

Then, from inside the container (3) through the communicating narrow tube (58),
Hydrogen is gradually released into the combustion chamber (53) of the catalyst holding part (5). This is because the internal pressure within the container (3) is higher than atmospheric pressure due to released hydrogen at the temperature at which the hand warmer (1) is used.

As mentioned above, the hydrogen dissociation parallel pressure of the hydrogen storage alloy (2) housed in this container is desirably more than 1 atm and less than 9 atm at room temperature, that is, about 20°C.

Hydrogen released from inside the container (3) comes into contact with the catalyst (4) in the combustion chamber (53) through the aforementioned route.

When hydrogen comes into contact with this catalyst (4), on the catalyst (4),
The oxidation reaction started at a temperature of -10°C or higher.

Therefore, even in winter or outdoors, if the temperature is at least 110° C. or higher, spontaneous ignition can be caused to start the oxidation reaction without the need for an ignition device like a conventional hand warmer.

As the release of hydrogen progresses by opening the seal of the container (3), the temperature gradually decreases due to the endothermic effect during hydrogen release, and at the same time, the hydrogen dissociation pressure also decreases. However, the aforementioned combustion heat of hydrogen is conducted to the container (3) and the container (3) itself becomes warm. Therefore, the hydrogen dissociation pressure can be prevented from decreasing due to the endothermic effect, and hydrogen can be continuously released from the hydrogen storage alloy (2).

This continuously released hydrogen comes into contact with the catalyst (4) through the same route as above and continues combustion.

The amount of hydrogen storage alloy (2), the type of hydrogen storage alloy (2) whose hydrogen dissociation equilibrium pressure at room temperature is 1 atm or more and less than 9 atm, and the amount of heat conducted to the container (3) during combustion. By making adjustments, it is possible to control the heat generation temperature of the hand warmer (1), its duration, etc.

In the example, 50 g of LaNi5 was used as the hydrogen storage alloy (2) that stored hydrogen, and a container (3) was used at room temperature.
), the pressure of hydrogen released from the hydrogen storage alloy (2) was adjusted to 2 to 4 atm, and the surface temperature of the catalyst was maintained at approximately 150°C for 5 to 6 hours. .

In addition, although the operating temperature for catalyst activity was initially set at about 100°C, water droplets were formed on the lower surface of the catalyst and the catalyst activity decreased. Therefore, by raising the combustion temperature to 150°C, the water turned into water vapor and evaporated into the atmosphere, resulting in stable catalytic combustion.

As mentioned above, according to the hand warmer heating method and hand warmer using a hydrogen storage alloy according to the invention of this application, the released hydrogen ignites simply by contacting the catalyst (4), so that it does not require the use of a conventional ignition device. is not necessary.

Furthermore, combustion generates only HzO and no COz, making it extremely clean and non-polluting.

〔Effect of the invention〕

This invention has the above-mentioned configuration, and the hydrogen gradually released from the hydrogen storage alloy (2) in which hydrogen is stored in the container (3) comes into contact with the catalyst (4) and is naturally absorbed. Since it ignites and generates heat, there is no need for a heat source for generating heat or a special ignition device, and it is possible to provide an odorless and pollution-free method of generating heat for a hand warmer and a hand warmer.

In addition, since it generates about three times as much heat per unit weight as benzene or the like, it is possible to provide a heating method and a hand warmer that generate a large amount of heat per unit weight.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the hand warmer according to the invention of this application, illustrating a state in which a container and a catalyst holding part are connected. FIG. 2 is a partially cutaway perspective view illustrating the same state as FIG. 1. (2)...Hydrogen storage alloy (3)...Container (4)
... Catalyst (7) ... Other catalyst

Claims (1)

[Claims] 1. A heating method for a hand warmer, in which hydrogen is gradually released from a sealed container (3) containing a hydrogen storage alloy (2) that has stored hydrogen, and the released hydrogen is brought into contact with a catalyst (4) and combusted. . 2. Hydrogen is gradually released by unsealing the container (3) in which the hydrogen storage alloy (2) has been stored, and the released hydrogen is brought into contact with the catalyst (4) and combusted. A method of generating heat for a hand warmer, comprising: gradually releasing hydrogen from the hydrogen storage alloy (2) in response to the heat of the combustion, and then bringing the released hydrogen into contact with the catalyst (4) and combusting it. 3. The heating method for a hand warmer according to claim 1 or 2, wherein another catalyst (7) whose surface is resistant to oxidation and has high low-temperature activity is mixed into the catalyst (4). 4. A container (3) in which a hydrogen storage alloy (2) that has stored hydrogen is sealed; a means for opening the container (3); and a means for contacting and burning the hydrogen released by opening the container (3). A hand warmer comprising a catalyst (4). 5. 5. The hand warmer according to claim 4, wherein said catalyst (4) contains another catalyst (7) whose surface is less likely to be oxidized and which has high low temperature activity.